Absent-mindedness is where a person shows inattentive or forgetful behaviour.[20] Absent-mindedness is a mental condition in which the subject experiences low levels of attention and frequent distraction. Absent-mindedness is not a diagnosed condition but rather a symptom of boredom and sleepiness which people experience in their daily lives. When suffering from absent-mindedness, people tend to show signs of memory lapse and weak recollection of recently occurring events. This can usually be a result of a variety of other conditions often diagnosed by clinicians such as attention deficit hyperactivity disorder and depression. In addition to absent-mindedness leading to an array of consequences affecting daily life, it can have as more severe, long-term problems.
Second, boredom typically occurs when people have trouble focusing their attention and they believe the reason for this difficulty is in the environment. When sitting in the airport, for example, there is probably a lot going on. There are people having conversations that you could listen to. You probably have something to read. There may be televisions showing the news. But, the stress of waiting for a delayed flight often makes it hard to concentrate, and so your mind jumps from one thing to another. You assume that this is caused by the environment, and so you feel boredom.

Martin Heidegger wrote about boredom in two texts available in English, in the 1929/30 semester lecture course The Fundamental Concepts of Metaphysics, and again in the essay What is Metaphysics? published in the same year. In the lecture, Heidegger included about 100 pages on boredom, probably the most extensive philosophical treatment ever of the subject. He focused on waiting at railway stations in particular as a major context of boredom.[25] Søren Kierkegaard remarks in Either/Or that "patience cannot be depicted" visually, since there is a sense that any immediate moment of life may be fundamentally tedious.

What can you do about boredom? Obviously, there are times when you are stuck. If you are listening to a lecture that you cannot leave, then you just need to find a way to get through it. When you have some control, though, use your understanding of boredom to help you out. If you can, try to do a meditation exercise to lower your arousal level. Also, keep some music handy. Music you enjoy can crowd out distractions in the environment. It can also influence your mood in positive ways to counteract the pain of being bored.  
In conventional usage, boredom is an emotional and occasionally psychological state experienced when an individual is left without anything in particular to do, is not interested in their surroundings, or feels that a day or period is dull or tedious. It is also understood by scholars as a modern phenomenon which has a cultural dimension. "There is no universally accepted definition of boredom. But whatever it is, researchers argue, it is not simply another name for depression or apathy. It seems to be a specific mental state that people find unpleasant—a lack of stimulation that leaves them craving relief, with a host of behavioural, medical and social consequences."[1] According to BBC News, boredom "...can be a dangerous and disruptive state of mind that damages your health"; yet research "...suggest[s] that without boredom we couldn't achieve our creative feats."[2]
Finally, a real problem caused by boredom is that it leads you to dislike the things that are the object of boredom. In my senior year of high school, for example, I was forced to read Moby Dick. I struggled to get interested in it and spent long hours staring at the pages trying to lose myself in it. To this day, I really do not like Moby Dick. The negative feelings that came with the boredom have stuck to the book.
“To me, at least in retrospect, the really interesting question is why dullness proves to be such a powerful impediment to attention. Why we recoil from the dull. Maybe it’s because dullness is intrinsically painful; maybe that’s where phrases like ‘deadly dull’ or ‘excruciatingly dull’ come from. But there might be more to it. Maybe dullness is associated with psychic pain because something that’s dull or opaque fails to provide enough stimulation to distract people from some other, deeper type of pain that is always there, if only in an ambient, low-level way, and which most of us spend nearly all our time and energy trying to distract ourselves from feeling, or at least from feeling directly or with our full attention. Admittedly, the whole thing’s pretty confusing, and hard to talk about abstractly…but surely something must lie behind not just Muzak in dull or tedious places any more but now also actual TV in waiting rooms, supermarkets’ checkouts, airport gates, SUVs’ backseats. Walkman, iPods, BlackBerries, cell phones that attach to your head. This terror of silence with nothing diverting to do. I can’t think anyone really believes that today’s so-called ‘information society’ is just about information. Everyone knows it’s about something else, way down.” 

When the antiproton was discovered … it sent a wave of ennui through the physics community. Not that its discovery was unimportant, but on the basis of Dirac's theory, everybody expected it. — Roger G. Newton, The Truth of Science, 1997 Chauncey and I were keen enough about our aesthetic solution to the ennui of war to try to proselytize others. He organized discussion groups with the crew; I took volunteers to visit landmarks … — Louis Auchincloss, "Atlantic War," in Authors at Sea, ed. Robert Shenk,  1997 The attendant outside was standing on tennis balls, exercising the soles of her feet, her body swaying back and forth with the ennui of jelly. — Edna O'Brien, New Yorker, 17 June 1991 Thus the days of life are consumed, one by one, without an object beyond the present moment; ever flying from the ennui of that, yet carrying it with us … — Thomas Jefferson, in a letter dated 7 Feb. 1787 Thomas Jefferson: Writings,  1984 the kind of ennui that comes from having too much time on one's hands and too little will to find something productive to do